was that used for? we'll find out hopefully in court and we can't remember reeva steenkamp. gets buried tomorrow, her parents, only child, friends have to say good bye to a young woman who seemed so beautiful and bubbly, and, of course, everybody here, asking that same question. why? why did he do it? what was the motivation? no answers on that one either. we'll keep you posted. back to you. >> robyn, thank you very much. that's all for us tonight. "anderson cooper" starts now. >>> thanks, piers, good evening, everyone. it's 10:00 p.m. on the east coast. a terrifying explanation of why adam lanza chose the target he did. and there is this. a face in the crowd when president obama was speaking out against kids being gunned down in chicago. just hours later, her young life was forever changed. also tonight, we've also been there. a crowded flight, a crying baby, but no matter how bad it gets, who would ever, ever slap the baby? we'll show you the man who did and speak with the baby's parents. >>> we begin with breaking news. a chilling answer to why did adam lanza target sandy hook elementary scho